We describe the current status of solar neutrino measurements and of the
theory -- both neutrino physics and solar astrophysics -- employed in
interpreting measurements. Important recent developments include
Super-Kamiokande's determination of the neutrino-electron elastic scattering
rate for 8B neutrinos to 3%; the latest SNO global analysis in which the
inclusion of low-energy data from SNO I and II significantly narrowed the range
of allowed values for the neutrino mixing angle theta12; Borexino results for
both the 7Be and pep neutrino fluxes, the first direct measurements
constraining the rate of ppI and ppII burning in the Sun; global reanalyses of
solar neutrino data that take into account new reactor results on theta13; a
new decadal evaluation of the nuclear physics of the pp chain and CNO cycle
defining best values and uncertainties in the nuclear microphysics input to
solar models; recognition of an emerging discrepancy between two tests of solar
metallicity, helioseismological mappings of the sound speed in the solar
interior, and analyses of the metal photoabsorption lines based on our best
current description of the Sun's photosphere; a new round of standard solar
model calculations optimized to agree either with helioseismology or with the
new photospheric analysis; and, motivated by the solar abundance problem, the
development of nonstandard, accreting solar models, in order to investigate
possible consequences of the metal segregation that occurred in the proto-solar
disk. We review this progress and describe how new experiments such as SNO+
could help us further exploit neutrinos as a unique probe of stellar interiors.Comment: 82 pages, 11 figure
